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Series description


Glandless circulation double pump with flange connection, EC motor and automatic power adjustment


Domestic hot water circulation systems of all kinds, hot-water heating systems of all kinds, air conditioning, closed cooling circuits, industrial circulating systems

Type key

Example:Wilo-Stratos‐ZD 40/1-8
StratosHigh-efficiency pump (flange-end pump), electronically controlled
ZDDouble pump for domestic hot water circulation
40/Nominal connection diameter
1-8Nominal delivery head range [m]

Special features/product advantages

  • Energy savings through greater system efficiency with the Q-Limit function (volume flow limiter)
  • Optimised display for better readability and operation
  • Space-saving installation due to compact design and location-dependent LC display
  • Modular concept for connection of all conventional bus systems (e.g. Modbus, BACnet, CAN, LON and PLR)
  • Dual pump management via retrofittable IF-Modules:
  • Tried and tested quality and reliability

Technical data

  • Energy efficiency index (EEI) ≤ 0.27
  • Permissible temperature range
    • Drinking water up to 3.57 mmol/l (20 °dH), 0 °C to +80 °C
    • Heating water ‐10 °C to +110 °C
  • Mains connection: 1~230 V, 50/60 Hz, 3~230 V, 50/60 Hz
  • Protection class IP X4D
  • Flange connection DN 32 to DN 40
  • Max. operating pressure, standard version: 6/10 bar (special version: 16 bar)


Operating modes

  • Manual control mode (n=constant)
  • Δp-c for constant differential pressure
  • Δp-v for variable differential pressure
  • Δp-T for temperature-controlled differential pressure (programmable via IR-Module, Wilo-IR-Stick, IR-Monitor, Modbus, BACnet, LON or CAN)
  • Q limit for limiting the maximum volume flow (setting only via IR-stick)

Manual functions

  • Setting the operating mode
  • Differential pressure setpoint setting
  • Setting automatic setback operation
  • Setting the pump ON/OFF
  • Setting the speed (manual control mode)

Automatic functions

  • Infinitely variable power adjustment according to the operating mode
  • Automatic setback operation
  • Deblocking function
  • Soft start
  • Full motor protection with integrated trip electronics

External control functions

  • "Overriding Off" control input (possible with Stratos IF-Modules)
  • "Overriding Min" control input (possible with Stratos IF-Modules)
  • "Analogue In 0 ‐ 10 V" control input (remote speed adjustment) (possible with Stratos IF-Modules)
  • "Analogue In 0 ‐ 10 V" control input (remote setpoint adjustment) (possible with Stratos IF-Modules)

Signal and display functions

  • Individual / collective fault signal (potential-free NC contact) (programmable with the IR-Monitor)
  • Collective fault signal (potential-free NC contact)
  • Individual run signal (potential-free NO contact) (possible with Stratos IF-Modules)
  • Fault signal light
  • LCD display for indication of pump data and fault codes

Data exchange

  • Infrared interface for wireless data exchange with IR-Module/Wilo-IR-Stick/IR-Monitor
  • Modbus RTU serial digital interface for connection to building automation BA via RS485 BUS system (possible with Stratos IF-Modules)
  • BACnet serial digital interface MS/TP slave for connection to building automation BA via RS485 BUS system (possible with Stratos IF-Modules)
  • CAN serial digital interface for connection to building automation BA via IF-Modules BUS system (possible with Stratos IF-Modules)
  • LON serial digital interface for connection to a LONWorks network (possible with Stratos IF-Modules)
  • PLR serial digital interface for connection to BA via Wilo interface converter or company-specific coupling modules (possible with Stratos IF-Modules)

Dual pump management (double pump or 2 x single pumps)

  • Main/standby operation (automatic fault-actuated switchover/time-dependent pump cycling): various combinations with Stratos IF-Modules (accessories) possible
  • Parallel operation (efficiency-optimised peak load activation and deactivation): various combinations with Stratos IF-Modules (accessories) possible


  • Flange versions:
    • Standard version for DN 32/DN 40 pumps: PN 6/10 combination flange (PN 16 flange according to EN 1092-2) for PN 6 and PN 16 counter flanges,
    • Special version for pumps DN 32 / DN 40: PN 16 flange (according to EN 1092-2) for PN 16 counter flange,
  • Double switchover valve in pump housing
  • Plug-in position for optional extension with Wilo-IF‐Modules


  • Pump housing: Grey cast iron
  • Thermal insulation: Polypropylene
  • Shaft: stainless steel
  • Bearing: Carbon, synthetic resin impregnated
  • Impeller: Plastic

Scope of delivery

  • Pump
  • Washers for flange screws (with nominal connection diameter DN 32 / DN 40)
  • Installation and operating instructions


  • Special versions for operating pressure PN 16 (at additional charge)


  • Blind flanges
  • IR-Module
  • IR-Stick
  • IR-Monitor
  • Stratos IF-Modules: Modbus, BACnet, CAN, LON, PLR, DP, Ext. Off, Ext. Min., SBM, Ext. Off/SBM

Special versions

Observe local information and instructions for the drinking water directive!

Duty chart

Duty chart


General overview

Edition 2017
Page format A4
Number of pages 72

PDF (46 MB)


IF-Modul LON / IF-Modul Stratos LON

Article Number 2165357
Edition 1603
Version number 01
Page format A4
Number of pages 48

PDF (1 MB)


Wilo-IF-Modul Stratos CAN

Article Number 2096947
Edition 1103
Version number 02
Page format A4
Number of pages 2

PDF (379 kB)


Wilo-Stratos / -D / -Z/ -ZD

Article Number 2120417-21
Edition 1604
Version number 04
Page format A5
Number of pages 57

PDF (3 MB)



Tipps & Guides

General Overview 2018

PDF: Wilo-Stratos-ZD


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